Ok, I've figured it out myself. The sad thing is, that all params are converted to JSON, which makes it impossible to pass a method / lambda as callback. Now I have just added a few lines to the 'on_finished' callback of 'ExecCommand' in 'Packages/Default/exec.py'. This works for me now, but it makes it impossible to publish such functionality as a plugin. I was trying to reopen the 'ExecCommand' class like in ruby, but this is apparently not possible

Any other ideas how I could inject my needed functionality into the 'ExecCommand' class?

Current versions of the exec command do print the exit code if it's non-zero.

With respect to editing the default exec command, you'd need to make a new command, either by copying it or subclassing from it, and then make your build system use your my_exec command via the target property in the build system.

jps wrote:Current versions of the exec command do print the exit code if it's non-zero.

I want to show the test panel automatically if the tests were failing. So I reckon, that this is not possible with the current implementation of 'exec'.

With respect to editing the default exec command, you'd need to make a new command, either by copying it or subclassing from it, and then make your build system use your my_exec command via the target property in the build system.

Of course, subclassing. Thought for some weird reason, that it wouldn't be possible, as it's some kind of default system functionality. Will try it.